I've never seen anything like this. Did a fresh install of x64 Nadia with Cinnamon. Everything was working fine, including sound. Was a little quiet, though, so I went to the volume icon in the tray and turned it up. Immediately, the sound went choppy, and to my surprise, the volume icon started flickering in time with it! Happens 1-2 times a second. I pulled up the audio options from the icon, and discovered that the whole audio gui seems to be doing this: the 'on/off' switch is toggling back and forth, the volume bar is jumping from 0% to whatever I set it to, multiple times a second. The problem persists after several reboots. Through my interaction with the gui sound interface, I seem to have triggered this erratic behavior - makes me wonder if it's a Cinnamon issue.

Did you do an apt-get update and update your header files? I know this sounds like a canned answer but it could help you. Just in case.

Also try an apt -get upgrade if that does not help.

This might take care of the problem. Also check the settings and look through the settings for the volume and sound in those options and see if your volume imput and output are set up correctly for your sound card on your computer.

No, that's a good place to start. Thanks for the recommendation. I sometimes forget that the latest download on the webpage isn't always the most up-to-date. Will follow up with this and see what happens.

New headers and updates didn't work. However, I have through further testing discovered that it's the 'Analog Stereo Duplex' sound source having the issue. Once I switch the output to the 4.1 or 5.1 surround setting, the issue goes away. A good stopgap fix, but I'm not sure what the implications will be through a range of audio applications. I'll report back if any come up.